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ovn-controller: Fix parsing of OVN tunnel IDs

Encap tunnel-ids are of the form:
<chassis-id><OVN_MVTEP_CHASSISID_DELIM><encap-ip>.
In physical_run we were checking if a tunnel-id corresponds
to the local chassis-id by searching if the chassis-id string
is included in the tunnel-id (strstr). This can break quite
easily, for example, if the local chassis-id is a substring
of a remote chassis-id. In that case we were wrongfully
skipping the tunnel creation.

To fix that new tunnel-id creation and parsing functions are added in
encaps.[ch]. These functions are now used everywhere where applicable.

Acked-by: Venu Iyer <iyervl@ymail.com>
Reported-at: https://bugzilla.redhat.com/1708131
Reported-by: Haidong Li <haili@redhat.com>
Fixes: b520ca7 ("Support for multiple VTEP in OVN")
Signed-off-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
This commit is contained in:
Dumitru Ceara
2019-06-12 17:59:02 +02:00
committed by Ben Pfaff
parent bb16fbccf9
commit db7a3c99e8
6 changed files with 117 additions and 56 deletions

View File

@@ -15,6 +15,7 @@
#include <config.h>
#include "bfd.h"
#include "encaps.h"
#include "lport.h"
#include "ovn-controller.h"
@@ -72,14 +73,16 @@ bfd_calculate_active_tunnels(const struct ovsrec_bridge *br_int,
const char *id = smap_get(&port_rec->external_ids,
"ovn-chassis-id");
if (id) {
char *chassis_name;
char *save_ptr = NULL;
char *tokstr = xstrdup(id);
chassis_name = strtok_r(tokstr, OVN_MVTEP_CHASSISID_DELIM, &save_ptr);
if (chassis_name && !sset_contains(active_tunnels, chassis_name)) {
sset_add(active_tunnels, chassis_name);
char *chassis_name = NULL;
if (encaps_tunnel_id_parse(id, &chassis_name,
NULL)) {
if (!sset_contains(active_tunnels,
chassis_name)) {
sset_add(active_tunnels, chassis_name);
}
free(chassis_name);
}
free(tokstr);
}
}
}
@@ -193,17 +196,17 @@ bfd_run(const struct ovsrec_interface_table *interface_table,
const char *tunnel_id = smap_get(&br_int->ports[k]->external_ids,
"ovn-chassis-id");
if (tunnel_id) {
char *chassis_name;
char *save_ptr = NULL;
char *tokstr = xstrdup(tunnel_id);
char *chassis_name = NULL;
char *port_name = br_int->ports[k]->name;
sset_add(&tunnels, port_name);
chassis_name = strtok_r(tokstr, OVN_MVTEP_CHASSISID_DELIM, &save_ptr);
if (chassis_name && sset_contains(&bfd_chassis, chassis_name)) {
sset_add(&bfd_ifaces, port_name);
if (encaps_tunnel_id_parse(tunnel_id, &chassis_name, NULL)) {
if (sset_contains(&bfd_chassis, chassis_name)) {
sset_add(&bfd_ifaces, port_name);
}
free(chassis_name);
}
free(tokstr);
}
}

View File

@@ -26,6 +26,13 @@
VLOG_DEFINE_THIS_MODULE(encaps);
/*
* Given there could be multiple tunnels with different IPs to the same
* chassis we annotate the ovn-chassis-id with
* <chassis_name>OVN_MVTEP_CHASSISID_DELIM<IP>.
*/
#define OVN_MVTEP_CHASSISID_DELIM '@'
void
encaps_register_ovs_idl(struct ovsdb_idl *ovs_idl)
{
@@ -78,6 +85,70 @@ tunnel_create_name(struct tunnel_ctx *tc, const char *chassis_id)
return NULL;
}
/*
* Returns a tunnel-id of the form 'chassis_id'-delimiter-'encap_ip'.
*/
char *
encaps_tunnel_id_create(const char *chassis_id, const char *encap_ip)
{
return xasprintf("%s%c%s", chassis_id, OVN_MVTEP_CHASSISID_DELIM,
encap_ip);
}
/*
* Parses a 'tunnel_id' of the form <chassis_name><delimiter><IP>.
* If the 'chassis_id' argument is not NULL the function will allocate memory
* and store the chassis-id part of the tunnel-id at '*chassis_id'.
* If the 'encap_ip' argument is not NULL the function will allocate memory
* and store the encapsulation IP part of the tunnel-id at '*encap_ip'.
*/
bool
encaps_tunnel_id_parse(const char *tunnel_id, char **chassis_id,
char **encap_ip)
{
/* Find the delimiter. Fail if there is no delimiter or if <chassis_name>
* or <IP> is the empty string.*/
const char *d = strchr(tunnel_id, OVN_MVTEP_CHASSISID_DELIM);
if (d == tunnel_id || !d || !d[1]) {
return false;
}
if (chassis_id) {
*chassis_id = xmemdup0(tunnel_id, d - tunnel_id);
}
if (encap_ip) {
*encap_ip = xstrdup(d + 1);
}
return true;
}
/*
* Returns true if 'tunnel_id' contains 'chassis_id' and, if specified, the
* given 'encap_ip'. Returns false otherwise.
*/
bool
encaps_tunnel_id_match(const char *tunnel_id, const char *chassis_id,
const char *encap_ip)
{
while (*tunnel_id == *chassis_id) {
if (!*tunnel_id) {
/* 'tunnel_id' and 'chassis_id' are equal strings. This is a
* mismatch because 'tunnel_id' is missing the delimiter and IP. */
return false;
}
tunnel_id++;
chassis_id++;
}
/* We found the first byte that disagrees between 'tunnel_id' and
* 'chassis_id'. If we consumed all of 'chassis_id' and arrived at the
* delimiter in 'tunnel_id' (and if 'encap_ip' is correct, if it was
* supplied), it's a match. */
return (*tunnel_id == OVN_MVTEP_CHASSISID_DELIM
&& *chassis_id == '\0'
&& (!encap_ip || !strcmp(tunnel_id + 1, encap_ip)));
}
static void
tunnel_add(struct tunnel_ctx *tc, const struct sbrec_sb_global *sbg,
const char *new_chassis_id, const struct sbrec_encap *encap)
@@ -94,8 +165,7 @@ tunnel_add(struct tunnel_ctx *tc, const struct sbrec_sb_global *sbg,
* combination of the chassis_name and the encap-ip to identify
* a specific tunnel to the chassis.
*/
tunnel_entry_id = xasprintf("%s%s%s", new_chassis_id,
OVN_MVTEP_CHASSISID_DELIM, encap->ip);
tunnel_entry_id = encaps_tunnel_id_create(new_chassis_id, encap->ip);
if (csum && (!strcmp(csum, "true") || !strcmp(csum, "false"))) {
smap_add(&options, "csum", csum);
}

View File

@@ -39,4 +39,10 @@ void encaps_run(struct ovsdb_idl_txn *ovs_idl_txn,
bool encaps_cleanup(struct ovsdb_idl_txn *ovs_idl_txn,
const struct ovsrec_bridge *br_int);
char *encaps_tunnel_id_create(const char *chassis_id, const char *encap_ip);
bool encaps_tunnel_id_parse(const char *tunnel_id, char **chassis_id,
char **encap_ip);
bool encaps_tunnel_id_match(const char *tunnel_id, const char *chassis_id,
const char *encap_ip);
#endif /* ovn/encaps.h */

View File

@@ -81,11 +81,4 @@ enum chassis_tunnel_type {
uint32_t get_tunnel_type(const char *name);
/*
* Given there could be multiple tunnels with different IPs to the same
* chassis we annotate the ovn-chassis-id with
* <chassis_name>OVN_MVTEP_CHASSISID_DELIM<IP>.
*/
#define OVN_MVTEP_CHASSISID_DELIM "@"
#endif /* ovn/ovn-controller.h */

View File

@@ -16,6 +16,7 @@
#include <config.h>
#include "binding.h"
#include "byte-order.h"
#include "encaps.h"
#include "flow.h"
#include "ha-chassis.h"
#include "lflow.h"
@@ -80,38 +81,27 @@ struct chassis_tunnel {
/*
* This function looks up the list of tunnel ports (provided by
* ovn-chassis-id ports) and returns the tunnel for the given chassid-id and
* encap-ip. The ovn-chassis-id is formed using the chassis-id and encap-ip as
* <chassis-id>OVN_MVTEP_CHASSISID_DELIM<encap-ip>. The list is hashed using
* the chassis-id. If the encap-ip is not specified, it means we'll just
* return a tunnel for that chassis-id, i.e. we just check for chassis-id and
* if there is a match, we'll return the tunnel. If encap-ip is also provided we
* use <chassis-id>OVN_MVTEP_CHASSISID_DELIM<encap-ip> to do a more specific
* lookup.
* encap-ip. The ovn-chassis-id is formed using the chassis-id and encap-ip.
* The list is hashed using the chassis-id. If the encap-ip is not specified,
* it means we'll just return a tunnel for that chassis-id, i.e. we just check
* for chassis-id and if there is a match, we'll return the tunnel.
* If encap-ip is also provided we use both chassis-id and encap-ip to do
* a more specific lookup.
*/
static struct chassis_tunnel *
chassis_tunnel_find(const char *chassis_id, char *encap_ip)
{
char *chassis_tunnel_entry;
/*
* If the specific encap_ip is given, look for the chassisid_ip entry,
* else return the 1st found entry for the chassis.
*/
if (encap_ip != NULL) {
chassis_tunnel_entry = xasprintf("%s%s%s", chassis_id,
OVN_MVTEP_CHASSISID_DELIM, encap_ip);
} else {
chassis_tunnel_entry = xasprintf("%s", chassis_id);
}
struct chassis_tunnel *tun = NULL;
HMAP_FOR_EACH_WITH_HASH (tun, hmap_node, hash_string(chassis_id, 0),
&tunnels) {
if (strstr(tun->chassis_id, chassis_tunnel_entry) != NULL) {
free (chassis_tunnel_entry);
if (encaps_tunnel_id_match(tun->chassis_id, chassis_id, encap_ip)) {
return tun;
}
}
free (chassis_tunnel_entry);
return NULL;
}
@@ -1064,8 +1054,9 @@ physical_run(struct ovsdb_idl_index *sbrec_port_binding_by_name,
}
const char *tunnel_id = smap_get(&port_rec->external_ids,
"ovn-chassis-id");
if (tunnel_id && strstr(tunnel_id, chassis->name)) {
"ovn-chassis-id");
if (tunnel_id &&
encaps_tunnel_id_match(tunnel_id, chassis->name, NULL)) {
continue;
}
@@ -1121,16 +1112,10 @@ physical_run(struct ovsdb_idl_index *sbrec_port_binding_by_name,
* where we need to tunnel to the chassis, but won't
* have the encap-ip specifically.
*/
char *tokstr = xstrdup(tunnel_id);
char *save_ptr = NULL;
char *hash_id = strtok_r(tokstr, OVN_MVTEP_CHASSISID_DELIM,
&save_ptr);
char *ip = strtok_r(NULL, "", &save_ptr);
/*
* If the value has morphed into something other than
* chassis-id>delim>encap-ip, ignore.
*/
if (!hash_id || !ip) {
char *hash_id = NULL;
char *ip = NULL;
if (!encaps_tunnel_id_parse(tunnel_id, &hash_id, &ip)) {
continue;
}
struct chassis_tunnel *tun = chassis_tunnel_find(hash_id, ip);
@@ -1151,7 +1136,8 @@ physical_run(struct ovsdb_idl_index *sbrec_port_binding_by_name,
tun->type = tunnel_type;
physical_map_changed = true;
}
free(tokstr);
free(hash_id);
free(ip);
break;
} else {
const char *iface_id = smap_get(&iface_rec->external_ids,
@@ -1256,7 +1242,8 @@ physical_run(struct ovsdb_idl_index *sbrec_port_binding_by_name,
struct match match = MATCH_CATCHALL_INITIALIZER;
if (!binding->chassis ||
strstr(tun->chassis_id, binding->chassis->name) == NULL) {
!encaps_tunnel_id_match(tun->chassis_id,
binding->chassis->name, NULL)) {
continue;
}

View File

@@ -22,6 +22,7 @@
#include "csum.h"
#include "dirs.h"
#include "dp-packet.h"
#include "encaps.h"
#include "flow.h"
#include "ha-chassis.h"
#include "lport.h"
@@ -2728,7 +2729,8 @@ get_localnet_vifs_l3gwports(
}
const char *tunnel_id = smap_get(&port_rec->external_ids,
"ovn-chassis-id");
if (tunnel_id && strstr(tunnel_id, chassis->name)) {
if (tunnel_id &&
encaps_tunnel_id_match(tunnel_id, chassis->name, NULL)) {
continue;
}
const char *localnet = smap_get(&port_rec->external_ids,